全文获取类型
收费全文 | 1012篇 |
免费 | 10篇 |
国内免费 | 34篇 |
专业分类
安全科学 | 50篇 |
废物处理 | 84篇 |
环保管理 | 93篇 |
综合类 | 88篇 |
基础理论 | 154篇 |
环境理论 | 1篇 |
污染及防治 | 382篇 |
评价与监测 | 142篇 |
社会与环境 | 52篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 27篇 |
2022年 | 131篇 |
2021年 | 101篇 |
2020年 | 39篇 |
2019年 | 44篇 |
2018年 | 57篇 |
2017年 | 65篇 |
2016年 | 61篇 |
2015年 | 26篇 |
2014年 | 40篇 |
2013年 | 125篇 |
2012年 | 46篇 |
2011年 | 56篇 |
2010年 | 41篇 |
2009年 | 28篇 |
2008年 | 26篇 |
2007年 | 27篇 |
2006年 | 21篇 |
2005年 | 11篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1964年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有1056条查询结果,搜索用时 47 毫秒
591.
This study was monitored to determine the changes in the micromineral and macromineral composition of common sole (Solea solea), striped red mullet (Mullus surmuletus), and whiting (Merlangius merlangus) throughout the year. Macromineral concentrations in edible parts of fish species were 444–1,559 mg/kg for Na, 1,975–5,130 mg/kg for K, 228–658 mg/kg for Mg, 187–1,105 mg/kg for Ca, and 2,341–7,341 for P, respectively. The highest mercury contents were found in the autumn months. While the highest protein and lowest fat values were found in the summer, the highest ash contents were found in the spring. Mercury content was found to be over the legislative limits in autumn samples for common sole and in summer for striped red mullet. Lead and cadmium contents of striped red mullet were found to be over the legislative limits throughout year. 相似文献
592.
Monitoring forest structure at landscape level: a case study of Scots pine forest in NE Turkey 总被引:1,自引:0,他引:1
This study aims to investigate the change in spatial-temporal configuration of secondary forest succession and generate measurements for monitoring the changes in structural plant diversity in Yaln?zçam Scots pine forest in NE Turkey from 1972 to 2005. The successional stages were mapped using the combination of Geographic Information System (GIS), Global Positioning System (GPS), aerial photos and high resolution satellite images (IKONOS). Forest structure and its relationship with structural plant diversity along with its changes over time were characterized using FRAGSTATS. In terms of spatial configuration of seral stages, the total number of fragments increased from 572 to 735, and mean size of patch (MPS) decreased from 154.97 ha to 120.60 ha over 33 years. The situation resulted in forestation serving appropriate conditions for plant diversity in the area. As an overall change in study area, there was a net increase of 1823.3 ha forest during the period with an average annual forestation rate of 55.25 ha year?1(0.4% per year). In conclusion, the study revealed that stand type maps of forest management plans in Turkey provide a great chance to monitor the changes in structural plant diversity over time. The study further contributes to the development of a framework for effective integration of biodiversity conservation into Multiple Use Forest Management (MUFM) plans using the successional stages as a critical mechanism. 相似文献
593.
Application of multivariate statistical approach to identify heavy metal sources in bottom soil of the Seyhan River (Adana), Turkey 总被引:1,自引:0,他引:1
M. Gurhan Yalcin Ali Tumuklu Mustafa Sonmez Dilek Satir Erdag 《Environmental monitoring and assessment》2010,164(1-4):311-322
In this study, freshly deposited soils were sampled from the Seyhan River (Turkey) from the exit of the Seyhan Dam to the Adana exit. Heavy metal contents were measured with X-ray fluorescence spectrometer. Multivariate statistical approach is used to identify the sources of heavy metals and other elements in soil samples. Considering the size of anomalies, metals are ranked as Co>Pb>Cr>Zn>Al. Based on the hierarchical cluster analysis results, three clusters were observed. P, Mg, Ti, Fe, Ca, Na, K, Al, Si, and Nb form the first cluster, Zn, Sr, Pb, and Cr associated as the second cluster, and Ba and Co form the third cluster. Three factors computed from principal component analysis are explained with a cumulative variance of 95%. The first factor is defined with “high background lithogenic factor” Co, the second factor with “local industrial factor” Pb, Cr, Ba, and Mg, and the third factor with “natural factor” Cr and Pb. 相似文献
594.
Mohammad Ali Hamzeh Majid Shah-hosseini Abdolmajid Naderi Beni 《Environmental monitoring and assessment》2013,185(2):1791-1807
In this study, the levels of natural and anthropogenic metal contamination (aluminum (Al), iron (Fe), manganese (Mn), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)) in surface sediments of three harbors along the Iranian coast of Gulf of Oman were examined and reported for the first time. Effect of grain size, mineralogy, normalization technique using Fe concentrations, and different sediment quality guidelines were discussed. Data from the harbors were compared with other harbors worldwide. Sediments inside the harbors are characterized by moderate and high levels of pollution by trace metals Cu (12–287 μg/g), Pb (11–1,780 μg/g), Zn (38–547 μg/g), Cr (70–2,370 μg/g), and Ni (31–116 μg/g). However, As and Cd did not show considerable pollution inside and outside the harbors. Considering that there is no industrial activity around the study harbors, the major sources of contamination in the harbors are repairing, fueling, greasing, and painting of fishing ships and boats. Mineralogy of sediments in the study area as well as trace metal concentration in reference samples taken from onshore geological units confirmed that natural inputs of Cd, Cu, Pb, and Zn in the harbors are very low while most of Ni and Cr contamination in the study area comes from erosion of ophiolitic mélange units at the North of Makran mountains. 相似文献
595.
596.
597.
598.
599.
Analysis of elemental concentration using ICP-AES and pathogen indicator in drinking water of Qasim Abad, District Rawalpindi, Pakistan 总被引:1,自引:0,他引:1
Shama Sehar Iffat Naz Naeem Ali Safia Ahmed 《Environmental monitoring and assessment》2013,185(2):1129-1135
The present study was conducted to investigate drinking water quality (groundwater) from water samples taken from Qasim Abad, a locality of approximately 5,000 population, situated between twin cities Rawalpindi and Islamabad in Pakistan. The main sources of drinking water in this area are water bores which are dug upto the depth of 250–280 ft in almost every house. The study consists of the determination of physico-chemical properties, trace metals, heavy metals, rare earth elements and microbiological quality of drinking water. The data showed the variation of the investigated parameters in samples as follows: pH 6.75 to 8.70, electrical conductivity 540 to 855 μS/cm, total dissolved solids 325.46 to 515.23 ppm and dissolved oxygen 1.50 to 5.64 mg/L which are within the WHO guidelines for drinking water quality. The water samples were analysed for 30 elements (aluminium, iron, magnesium, manganese, silicon, zinc, molybdenum, titanium, chromium, nickel, tungsten, silver, arsenic, boron, barium, beryllium, cadmium, cobalt, copper, gallium, mercury, lanthanum, niobium, neodymium, lead, selenium, samarium, tin, vanadium and zirconium) by using inductively coupled plasma atomic emission spectroscopy. The organic contamination was detected in terms of most probable number (MPN) of faecal coliforms. Overall, elemental levels were lower than the recommended values but three water bores (B-1, B-6, B-7) had higher values of iron (1.6, 2.206, 0.65 ppm), two water bores (B-1, B-6) had higher values of aluminium (0.95, 1.92 ppm), respectively, and molybdenum was higher by 0.01 ppm only in one water bore (B-11). The total number of coliforms present in water samples was found to be within the prescribed limit of the WHO except for 5 out of 11 bore water samples (B-2, B-3, B-4, B-8, B-11), which were found in the range 5–35 MPN/100 mL, a consequence of infiltration of contaminated water (sewage) through cross connection, leakage points and back siphoning. 相似文献
600.
Bilal Hussain Tayyaba Sultana Salma Sultana K. A. Al-Ghanim Shahreef Masood Muhammad Ali Shahid Mahboob 《Environmental monitoring and assessment》2017,189(3):115
This study investigates the potential of the comet and micronucleus assays of fish DNA as a means of screening the toxicity of aquatic environments. Catla catla and Cirrhinus mrigala collected from the River Chenab in Pakistan were used as a case study for the application of comet and micronucleus techniques. Comet and micronucleus assays were used to compare DNA damage in C. catla and C. mrigala collected from polluted areas of the River Chenab and farmed fish. Atomic absorption spectrophotometry showed an acute level of toxicity from Cd, Cu, Mn, Zn, Pb, Cr, Sn, and Hg in river water. Comet assay showed significant (p < 0.05) DNA damage in C. catla representing 17.33 ± 2.42, 11.53 ± 2.14, and 14.17% DNA in the comet tail, averaged from three sites of the polluted area of the river. Tail moment was observed as 10.06 ± 2.71, 3.11 ± 0.74, and 14.70 ± 1.89, while olive moment was 8.85 ± 1.84, 3.83 ± 0.76, and 7.11 ± 0.73, respectively. Highly significant (p < 0.01) damage was reported in C. mrigala as 37.29 ± 2.51, 34.96 ± 2.53, and 38.80 ± 2.42% DNA in comet tail, tail moment was 23.48 ± 3.90, 19.78 ± 4.26, and 14.30 ± 1.82, and olive moment was 16.22 ± 2.04, 13.83 ± 1.96, and10.99 ± 0.90. Significant (p < 0.05) differences were observed in genotoxicity between farmed and polluted area fish. Micronucleus assay showed a similar picture of significant difference in respect to single and double micronucleus induction: i.e., 23.20 ± 4.19 and 2.80 ± 1.07‰ in C. catla and 44.80 ± 3.73 and 06.20 ± 0.97‰, respectively, in C. mrigala. Nuclear abnormalities were found as 6.00 ± 0.84 and 09.60 ± 1.72/thousand cells, respectively, in both species. The results of this study suggest that these novel fish DNA damage assays can be used as an expedient toxicity screening for aquatic environments. 相似文献